Bending Fault Detection of Few Mode Fiber Link Based on Multi-mode Transmission Reflection Analysis

In this paper, a bending fault detection method for few mode fiber based on multi-mode transmission reflection analysis (MM-TRA) is proposed. By launching unmodulated continuous-wave optical lights into the corresponding spatial modes of the FMF, the transmitted and reflected or backscattered optical power of different spatial modes can be measured and quantitatively analyzed to accurately detect and locate the bending fault. The results show that the localization errors of 40km FMF bending are less than 5.8 m when the mode combination of LP01 and LP11 is used, showing a good fault localization effect.